Method and apparatus for discovering small cell in heterogeneous communication network

Abstract

The invention provides a solution to discover a small cell in a heterogeneous communication network. A macro base station (10) judges whether a user equipment (20) has approached to a target region (S111, S112, S120) that includes one or more candidate small cells based upon stored location range information of all candidate small cells in a macro cell and estimated position information of the user equipment and judges (S130) whether to instruct the user equipment to perform a periodical measurement on the one or more candidate small cells to discover small cells, and if so, obtains density information (S141) that indicates a density of the candidate small cells in the target region, determines (S142) an interval for the periodical measurement of the user equipment based upon the obtained density information and transmits (S143, S210) a first signaling to the user equipment to instruct the user equipment to perform the periodical measurement at the determined interval. The invention can discover / identify a small cell in a heterogeneous communication network more efficiently while saving power consumption of the user equipment.

Description

FIELD OF THE INVENTION[0001]The present disclosure relates to a heterogonous communication network (HetNet) and particularly to a method and apparatus for discovering a small cell in a heterogonous communication network.BACKGROUND OF THE INVENTION[0002]An existing solution to discovering / identifying a cell for a Closed Subscriber Group (CGS) is achieved based on an Autonomous Search Function (ASF) and a proximity indication mechanism, with one of its important goals being for reduced power consumption of a user equipment. In this solution, a white list stored at the user equipment side includes cell IDs of a limited number of CGS cells associated therewith. Moreover the user equipment has information stored therein about the limited number of CGS cells associated therewith, e.g., location range information, radio fingerprint information, etc. The user equipment judges whether it has approached to one or more of the CGS cells in its white list according to the stored location range i...

AI Technical Summary

Benefits of technology

The patent text describes a method for optimizing the measurement and discovery of small cells in a wireless network. By determining the density of small cells in a target region, the method can adjust the measurement interval accordingly to save power and prolong the battery life of user equipment. In cases where the small cells are denser, the measurement interval is reduced to lower power consumption. Conversely, in areas where the small cells are less dense, the measurement interval is increased to improve discovery. The method also takes into account the likelihood of the user equipment leaving the coverage area of a small cell quickly, and can prioritize the discovery of small cells that can offload traffic from the macro cell to improve quality of service. Overall, the method ensures efficient and effective discovery of small cells while optimizing power consumption and reducing signaling overhead.

Problems solved by technology

However due to a large number of public pico cells, it may be impossible for the user equipment to store information regarding all these public pico cells, so the existing solution to discovering a CGS cell may not be applicable to discovering / identifying a public pico cell.

At present a public pico cell is discovered / identified simply in an exhaustive search, thus resulting in considerable power consumption of the user equipment.

In addition to the foregoing problem of considerable power consumption, the existing solution to discovering a CSG cell makes use of an s-measurement criterion based upon Reference Signal Receiving Power (RSRP), but this criterion is not sufficient to discover pico cells located in proximity to a base station of a serving macro cell because RSRP of the serving macro cell is still sufficiently high even if the user equipment is very close these pico cells.

Moreover with a solution based upon Reference Signal Received Quality (RSRP), a pico cell can be discovered with inter-cell interference, but this solution is only applicable to discovering an intra-frequency pico cell but not sufficient to discover an inter-frequency pico cell because the inter-frequency pico cell will not bring inter-cell interference to a macro cell.

Furthermore the user equipment has to perform an inter-frequency measurement to discover / identify an inter-frequency pico cell, and power consumption required for the inter-frequency measurement is more than that of intra-frequency measurement due to a limited interval configured for the inter-frequency measurement.

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